The Bristol Avon, also known as the Bath Avon, is a great river for canoeing. The river itself winds down a pretty valley in its lower reaches.
There are numerous weirs, and in high levels these are best avoided. Portages are a bit awkward too, so this is best done in medium conditions when the weirs can normally be climbed down at the sides.
Experienced kayakers and even open canoeists will be able to run many of the weirs in the right conditions, but they can be dangerous.
The Kennet and Avon canal runs parallel to the river in many parts, and it is therefore possible to arrange circular routes, going up on the canal and down on the river.